diff --git a/backend/internal/db/files.sql.go b/backend/internal/db/files.sql.go
index 6714d89..eb28325 100644
--- a/backend/internal/db/files.sql.go
+++ b/backend/internal/db/files.sql.go
@@ -14,7 +14,7 @@ import (
 const createFile = `-- name: CreateFile :one
 INSERT INTO files (id, name, mime_type, size, storage_key, checksum, created_at, updated_at)
 VALUES ($1, $2, $3, $4, $5, $6, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
-RETURNING id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id
+RETURNING id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id
 `
 
 type CreateFileParams struct {
@@ -46,7 +46,6 @@ func (q *Queries) CreateFile(ctx context.Context, arg CreateFileParams) (File, e
 		&i.OcrText,
 		&i.CreatedAt,
 		&i.UpdatedAt,
-		&i.IsFolder,
 		&i.ParentFileID,
 	)
 	return i, err
@@ -55,7 +54,7 @@ func (q *Queries) CreateFile(ctx context.Context, arg CreateFileParams) (File, e
 const createFolder = `-- name: CreateFolder :one
 INSERT INTO files (id, name, created_at, updated_at)
 VALUES ($1, $2, CURRENT_TIMESTAMP, CURRENT_TIMESTAMP)
-RETURNING id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id
+RETURNING id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id
 `
 
 type CreateFolderParams struct {
@@ -76,7 +75,6 @@ func (q *Queries) CreateFolder(ctx context.Context, arg CreateFolderParams) (Fil
 		&i.OcrText,
 		&i.CreatedAt,
 		&i.UpdatedAt,
-		&i.IsFolder,
 		&i.ParentFileID,
 	)
 	return i, err
@@ -93,7 +91,7 @@ func (q *Queries) DeleteFile(ctx context.Context, id string) error {
 }
 
 const getFile = `-- name: GetFile :one
-SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id FROM files
+SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id FROM files
 WHERE id = $1 LIMIT 1
 `
 
@@ -110,14 +108,14 @@ func (q *Queries) GetFile(ctx context.Context, id string) (File, error) {
 		&i.OcrText,
 		&i.CreatedAt,
 		&i.UpdatedAt,
-		&i.IsFolder,
 		&i.ParentFileID,
 	)
 	return i, err
 }
 
 const listFiles = `-- name: ListFiles :many
-SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id FROM files
+SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id FROM files
+WHERE parent_file_id IS NULL
 ORDER BY created_at DESC
 `
 
@@ -140,7 +138,6 @@ func (q *Queries) ListFiles(ctx context.Context) ([]File, error) {
 			&i.OcrText,
 			&i.CreatedAt,
 			&i.UpdatedAt,
-			&i.IsFolder,
 			&i.ParentFileID,
 		); err != nil {
 			return nil, err
@@ -157,7 +154,7 @@ func (q *Queries) ListFiles(ctx context.Context) ([]File, error) {
 }
 
 const listFilesByID = `-- name: ListFilesByID :many
-SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id FROM files
+SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id FROM files
 WHERE id = ANY($1::text[])
 ORDER BY created_at DESC
 `
@@ -181,7 +178,6 @@ func (q *Queries) ListFilesByID(ctx context.Context, dollar_1 []string) ([]File,
 			&i.OcrText,
 			&i.CreatedAt,
 			&i.UpdatedAt,
-			&i.IsFolder,
 			&i.ParentFileID,
 		); err != nil {
 			return nil, err
@@ -198,8 +194,8 @@ func (q *Queries) ListFilesByID(ctx context.Context, dollar_1 []string) ([]File,
 }
 
 const listFolders = `-- name: ListFolders :many
-SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, is_folder, parent_file_id FROM files
-WHERE is_folder = true
+SELECT id, name, mime_type, size, storage_key, checksum, ocr_text, created_at, updated_at, parent_file_id FROM files
+WHERE parent_file_id IS NOT NULL
 ORDER BY created_at DESC
 `
 
@@ -222,7 +218,6 @@ func (q *Queries) ListFolders(ctx context.Context) ([]File, error) {
 			&i.OcrText,
 			&i.CreatedAt,
 			&i.UpdatedAt,
-			&i.IsFolder,
 			&i.ParentFileID,
 		); err != nil {
 			return nil, err
diff --git a/backend/internal/db/models.go b/backend/internal/db/models.go
index ec218b0..06a88c8 100644
--- a/backend/internal/db/models.go
+++ b/backend/internal/db/models.go
@@ -19,7 +19,6 @@ type File struct {
 	OcrText      string         `json:"ocr_text"`
 	CreatedAt    time.Time      `json:"created_at"`
 	UpdatedAt    time.Time      `json:"updated_at"`
-	IsFolder     bool           `json:"is_folder"`
 	ParentFileID sql.NullString `json:"parent_file_id"`
 }
 
diff --git a/backend/internal/db/queries/files.sql b/backend/internal/db/queries/files.sql
index 0fdc4c1..9f99ebc 100644
--- a/backend/internal/db/queries/files.sql
+++ b/backend/internal/db/queries/files.sql
@@ -4,11 +4,12 @@ WHERE id = $1 LIMIT 1;
 
 -- name: ListFiles :many
 SELECT * FROM files
+WHERE parent_file_id IS NULL
 ORDER BY created_at DESC;
 
 -- name: ListFolders :many
 SELECT * FROM files
-WHERE is_folder = true
+WHERE parent_file_id IS NOT NULL
 ORDER BY created_at DESC;
 
 -- name: ListFilesByID :many
diff --git a/backend/internal/db/tags.sql.go b/backend/internal/db/tags.sql.go
index dda5a33..1ee2194 100644
--- a/backend/internal/db/tags.sql.go
+++ b/backend/internal/db/tags.sql.go
@@ -64,7 +64,7 @@ func (q *Queries) DeleteTag(ctx context.Context, id string) error {
 }
 
 const getFilesByTagID = `-- name: GetFilesByTagID :many
-SELECT f.id, f.name, f.mime_type, f.size, f.storage_key, f.checksum, f.ocr_text, f.created_at, f.updated_at, f.is_folder, f.parent_file_id FROM files f
+SELECT f.id, f.name, f.mime_type, f.size, f.storage_key, f.checksum, f.ocr_text, f.created_at, f.updated_at, f.parent_file_id FROM files f
 JOIN file_tags ft ON f.id = ft.file_id
 WHERE ft.tag_id = $1
 ORDER BY f.created_at DESC
@@ -89,7 +89,6 @@ func (q *Queries) GetFilesByTagID(ctx context.Context, tagID sql.NullString) ([]
 			&i.OcrText,
 			&i.CreatedAt,
 			&i.UpdatedAt,
-			&i.IsFolder,
 			&i.ParentFileID,
 		); err != nil {
 			return nil, err